1. Field of the Invention (Technical Field)
The present invention relates to mortars and more particularly to a diffuser for a mortar barrel that is configured to provide a surface for instrumentation installation that is unaffected by the mortar blast.
2. Background Art
There is a need to provide a non invasive port in close proximity and perpendicular to the mortar round axis of travel during firing without penetrating the mortar tube or path of mortar travel and without obstructing the flow of propellant gases. This invention being necessary to attach various analytical instrumentation for the collection of real time data to aid in the functions of the mortar fire control system (MFCS) and in the operational evaluation of the 120 mm mortar through attachment on the end of the 120 mm mortar barrel. The requirements to collect data on the mortar round and the operating parameters of the 120 mm mortar are very restrictive due to the destructive nature, extreme physical environment, and the engineering techniques involved interfacing the monitoring instrumentation which can survive in this environment.
The problem with discharge of the spent propellant gases through the existing smooth wall conical venturi produces an uneven flow and pressure build up between the mortar round and a random section of the wall of the venturi which occurs as the mortar round exits the barrel. The diverging conical wall of the existing blast attenuator device (BAD) provides no means of porting the gases along the wall without asymmetrically disturbing the gas flow path and no method to control a gap dimension between the mortar round and the in situ instrument interface.
Some prior art methods and devices have been provided to solve the problem in the past by using a cylindrical interface collar between the mortar barrel end and the BAD effectively lengthening the overall dimension of the barrel and position of the BAD discharge cone in reference to its mounted carrier, like in a M1064 vehicle.
The disadvantages and shortcomings of this previous approach is that a cylindrical interface collar, aside from exceeding the overall length restrictions, does not provide a sufficient increase in volume for the expansion and reduction of discharge gas pressure at the muzzle end of the barrel when the necessary gap dimension is maintained thereby imparting additional effective length to the muzzle end of the barrel.
These prior art approaches do not provide a combined instrument interface and a blast attenuation function for a mortar.